The fabrication of electrical devices, such as resistors, capacitors, and inductors, in integrated devices is well known. Typically, integrated electrical devices are formed by embedding appropriate materials in a substrate. The resulting integrated electrical device typically has relatively fixed electrical characteristics. However, in many applications, the electrical characteristics of such devices must be varied, depending upon the requirements of the given application, including feedback from the output or other circuit requirements to vary the electrical characteristics. Thus, a number of techniques have been proposed or suggested for varying the electrical characteristics of integrated electrical devices in order to maintain the electrical characteristics within specified limits. U.S. Pat. No. 5,543,765, for example, discloses electronic elements having variable electrical characteristics. The electronic elements include a cavity in which a moving insulator element shifts. The moving insulator element is partially covered with an electrically conductive material. An electrical field shifts the moving element to thereby vary the electrical characteristics of the electronic element.
While such proposed techniques may provide a mechanism for maintaining electrical characteristics within a specified range, they often have power or surface area requirements (or both) that are not practical within the constraints of commercially viable integrated devices. A need therefore exists for improved techniques for varying the electrical characteristics of integrated electrical devices in both real time and/or with a feedback. mechanism